M.B. Bos

Effect of a high monounsaturated fatty acids diet and a Mediterranean diet on serum lipids and insulin sensitivity in adults with mild abdominal obesity

BACKGROUND AND AIMS Diets high in monounsaturated fatty acids (MUFA) such as a Mediterranean diet may reduce the risk of cardiovascular diseases by improving insulin sensitivity and serum lipids. Besides being high in MUFA, a Mediterranean diet also contains abundant plant foods, moderate wine and low amounts of meat and dairy products, which may also play a role. We compared the effects of a high MUFA-diet with a diet high in saturated fatty acids (SFA) and the additional effect of a Mediterranean diet on insulin sensitivity and serum lipids. METHODS AND RESULTS A randomized parallel controlled-feeding trial was performed, in 60 non-diabetics (40-65 y) with mild abdominal obesity. After a two week run-in diet high in SFA (19 energy-%), subjects were allocated to a high MUFA-diet (20 energy-%), a Mediterranean diet (MUFA 21 energy-%), or the high SFA-diet, for eight weeks. The high MUFA and the Mediterranean diet did not affect fasting insulin concentrations. The high MUFA-diet reduced total cholesterol (-0.41 mmol/L, 95% CI -0.74, -0.09) and LDL-cholesterol (-0.38 mmol/L, 95% CI -0.65, -0.11) compared with the high SFA-diet, but not triglyceride concentrations. The Mediterranean diet increased HDL-cholesterol concentrations (+0.09 mmol/L, 95% CI 0.0, 0.18) and reduced the ratio of total cholesterol/HDL-cholesterol (-0.39, 95% CI -0.62, -0.16) compared with the high MUFA-diet. CONCLUSION Replacing a high SFA-diet with a high MUFA or a Mediterranean diet did not affect insulin sensitivity, but improved serum lipids. The Mediterranean diet was most effective, it reduced total and LDL-cholesterol, and also increased HDL-cholesterol and reduced total cholesterol/HDL-cholesterol ratio.

The prevalence of the metabolic syndrome is increased in patients with GH deficiency, irrespective of long-term substitution with recombinant human GH

OBJECTIVES Many reports demonstrate improvements in cardiovascular risk factors during GH replacement (rhGH) in adult GH deficiency (GHD). However, it remains to be determined to what extent these changes translate into a reduction of increased cardiovascular morbidity and mortality. The aim of this study was to evaluate the effects of long-term rhGH replacement on the prevalence of the metabolic syndrome (MS). Design, settings, main outcome measures: The MS was scored by the National Cholesterol Education Program-Adult Treatment Panel III definition in 50 consecutive GHD patients (45 +/- 9 years of age), before and after 2 and 5 years of rhGH replacement, and the data of untreated patients were compared with the general population using data from a Dutch population-based study (n=1062, 44 +/- 8 years of age). RESULTS Hypertriglyceridaemia (46.0 vs 18.5%, P<0.0001), hypertension (66.0 vs 35.5%, P<0.0001) and abdominal obesity (38.0 vs 23.4%, P=0.0178) were more prevalent in untreated patients when compared with controls, resulting in a higher prevalence of the MS in patients (38.0 vs 15.7%, P<0.0001). During rhGH replacement at a mean dose of 0.5 +/- 0.2 mg/day resulting in IGF-I concentrations in the normal age-adjusted reference range, mean high-density lipoprotein cholesterol level increased compared with baseline (P<0.001). However, the prevalence of (components of) the MS did not change after 2 or 5 years of treatment with rhGH. CONCLUSION In this study, the prevalence of the MS in patients with GHD is increased compared with healthy controls, irrespective of rhGH replacement.

Consumption of a High Monounsaturated Fat Diet Reduces Oxidative Phosphorylation Gene Expression in Peripheral Blood Mononuclear Cells of Abdominally Overweight Men and Women

The Mediterranean (MED) diet is often considered health-promoting due to its high content of MUFA and polyphenols. These bioactive compounds can affect gene expression and accordingly may regulate pathways and proteins related to cardiovascular disease prevention. This study aimed to identify the effects of a MED-type diet, and the replacement of SFA with MUFA in a Western-type diet, on peripheral blood mononuclear cell (PBMC) gene expression and plasma proteins. Abdominally overweight men and women (waist: women ≥80 cm, men ≥94 cm) were allocated to an 8-wk, completely controlled SFA diet (19% daily energy as SFA), a MUFA diet (20% daily energy MUFA), or a MED diet (21% daily energy MUFA). Concentrations of 124 plasma proteins and PBMC whole-genome transcriptional profiles were assessed. Consumption of the MUFA and MED diets, compared with the SFA diet, decreased the expression of oxidative phosphorylation (OXPHOS) genes, plasma connective tissue growth factor, and apoB concentrations. Compared with the MED and SFA diets, the MUFA diet changed the expression of genes involved in B-cell receptor signaling and endocytosis signaling. Participants who consumed the MED diet had lower concentrations of proinflammatory proteins at 8 wk compared with baseline. We hypothesize that replacement of SFA with MUFA may improve health, thereby reducing metabolic stress and OXPHOS activity in PBMC. The MED diet may have additional antiatherogenic effects by lowering proinflammatory plasma proteins.

Plasma Protein Profiling Reveals Protein Clusters Related to BMI and Insulin Levels in Middle-Aged Overweight Subjects

Background Biomarkers that allow detection of the onset of disease are of high interest since early detection would allow intervening with lifestyle and nutritional changes before the disease is manifested and pharmacological therapy is required. Our study aimed to improve the phenotypic characterization of overweight but apparently healthy subjects and to identify new candidate profiles for early biomarkers of obesity-related diseases such as cardiovascular disease and type 2 diabetes. Methodology/Principal Findings In a population of 56 healthy, middle-aged overweight subjects Body Mass Index (BMI), fasting concentration of 124 plasma proteins and insulin were determined. The plasma proteins are implicated in chronic diseases, inflammation, endothelial function and metabolic signaling. Random Forest was applied to select proteins associated with BMI and plasma insulin. Subsequently, the selected proteins were analyzed by clustering methods to identify protein clusters associated with BMI and plasma insulin. Similar analyses were performed for a second population of 20 healthy, overweight older subjects to verify associations found in population I. In both populations similar clusters of proteins associated with BMI or insulin were identified. Leptin and a number of pro-inflammatory proteins, previously identified as possible biomarkers for obesity-related disease, e.g. Complement 3, C Reactive Protein, Serum Amyloid P, Vascular Endothelial Growth Factor clustered together and were positively associated with BMI and insulin. IL-3 and IL-13 clustered together with Apolipoprotein A1 and were inversely associated with BMI and might be potential new biomarkers. Conclusion/ Significance We identified clusters of plasma proteins associated with BMI and insulin in healthy populations. These clusters included previously reported biomarkers for obesity-related disease and potential new biomarkers such as IL-3 and IL-13. These plasma protein clusters could have potential applications for improved phenotypic characterization of volunteers in nutritional intervention studies or as biomarkers in the early detection of obesity-linked disease development and progression.